﻿<p><em>IfcMaterial</em> is a homogeneous or inhomogeneous
substance that can be used to form elements (physical products or
their components).</p>
<p><em>IfcMaterial</em> is the basic entity for material
designation and definition; this includes identification by name
and classification (via reference to an external classification),
as well as association of material properties (isotropic or
anisotropic) defined by (subtypes of)
<em>IfcMaterialProperties</em>. An instance of <em>IfcMaterial</em>
may be associated to an element or element type using the
<em>IfcRelAssociatesMaterial</em> relationship. The assignment
might either be direct as a single material information, or
via</p>
<ul>
<li>a material layer set</li>
<li>a material profile set</li>
<li>a material constituent set</li>
</ul>
<p>An <em>IfcMaterial</em> may also have presentation information associated. Such presentation information is provided by
<em>IfcMaterialDefinitionRepresentation</em>, associating curve styles, hatching definitions or surface colouring/rendering
information to a material.</p>

<blockquote class="history">
HISTORY New entity in IFC4
</blockquote>

<blockquote class="change-ifc2x4">
IFC4 CHANGE  The attributes <em>Description</em> and <em>Category</em> have been added.
</blockquote>